[JesseK]

I recommend using single solenoid on your shifting transmissions. Then set the 'default' gear to what you plan to start autonomous in. That way it is impossible for the drive team to forget what gear they need to put the robot in, because it happens automatically.

Other than that, there are a couple of things to mitigate the imbalance.

First, one gearbox may require more force to shift than the other, and therefore there is more hysteresis in the shifting cylinder, causing a delay. To determine if this is an issue, disconnect the air tubes, turn the robot off and then manually shift from one speed to the other. If one gets 'stuck', then you may need to gently file the inside of the dog gear until it works. In rare cases the pneumatic cylinder may be bad. We had to do file one of our dog gears this year - no big deal if the gearbox is already apart.

The next way to mitigate it, mentioned above, is to make sure the lines to both sides are the same length. Also, remove all flow control valves from the cylinders.

Finally, your driver may be able to mitigate it some by slowing down/stopping before it shifts.